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Symptoms can include palpitations, breathlessness, dizziness or chest pain.

What is atrial fibrillation (AF)?

It's a heart rhythm disorder that causes an irregularly irregular heart-rate. It's the most common, sustained heart rhythm disorder, and it's prevalence is increasing as it increases with age. In AF, the normal regular rhythmic activity of the upper chambers or atria is replaced by chaotic irregular activity. The top chamber of the heart doesn't contract properly, and so blood clots can form within it.

What are its symptoms?

Symptoms can include palpitations, breathlessness, dizziness or chest pain. Some people may even black out if their heart-rate is very fast. Unfortunately up to 70% of individuals have no symptoms and sometimes the first diagnosis of AF is when a patient suffers from stroke — and AF is found to be the cause. If an irregular pulse is felt AF can be confirmed with an electrocardiogram (ECG).

What are the risks associated with it?

A person with AF is five times more likely to have a stroke — the effects of which can be much worse than a stroke from another causes, such as high blood pressure. AF doubles mortality because of the risk of stroke, and heart failure.

Can it be prevented?

AF can be prevented and if it occurs is very treatable, too. High blood-pressure and obesity lead to an increased risk of developing AF, losing weight and controlling blood pressure can help reduce this risk. AF is also associated with excess coffee and alcohol and other diseases such as thyroid disease, lung disease, diabetes and sleep apnoea.

How is it treated?

Treatment options are heart rate control with tablets and a blood-thinner to reduce the risk of clots forming causing a stroke. In patients with symptoms, rhythm control with stronger medication or with electric shock treatment called cardioversion can be performed and for some people a more definitive treatment called an ablation can be successful. This is an invasive procedure where a catheter is placed into the heart and radio-frequency energy or cryo therapy ablates the area causing the abnormal rhythm.